Author Updates

We finally had a chance for the household to go ahead and make some shields.
CleanlinessThis was tricky, I don't have gloves, but do have a face mask each that covers our mouths and noses. So, I would not count these masks as sterile and as such have been careful to pass on that information to recipients.
So we had frequent hand washes and (for what its worth) baby wipes to wipe down the plastic that gets a bit of a dirty residue from the smoke produced dur

I have recently been updating the Computer Vision chapter of the third edition of my Raspberry Pi Cookbook. Way back when I was writing the seconds edition, I decided to use the SimpleCV wrapper to OpenCV because it was -- well very simple to use.

SimpleCV is no longer maintained and in any case requires Python2. So the chapter's code needed to be changed to use OpenCV directly. Here's what I had to do on a Raspberry Pi 4 running Raspbian Buster (10).

Reading about flash memory, I was staggered by the astronomical number of transistors in such a small place I decided to see what it would take to make one of these using 1960s technology.

Flash Memory: Lets go with a modest 32GB micro-SD card.
Transistor: I'll use a TO-18 package transistor. If like me you are from the UK and of a certain age, then the BC108 or BC109 will bring fond memories of Wireless World magazine and minor soldering inju

I've recently spent some time developing the MonkMakes CO2 Sensor for micro:bit and have spent a fair amount of time researching into indoor air quality. It struck me that I actually had no idea how healthy (or otherwise) the air is, in the house that I both sleep and work in.
Time for a project! What's more I can reuse some of the sensors that I have accumulated while researching. These are low cost sensors, the whole lot costing probably less that GBP 50 (USD 50).
The project

Desoldering through-hole components with two or three legs, is pretty straightforward. Apply heat and some fresh solder to the underside and pull them out from the top. But when it comes to chips and modules with more pins, this approach doesn't work. Some people manage to master the use of the small pen-shaped 'solder-suckers'. The idea is that you melt the solder with an iron, and as soon as the solder is molten, place the solder-sucker over the joint and release the spring to suck up the

Last week I found myself in front of a room full of Cubans in Havana, delivering a course on Arduino in broken Spanish. Was this a variation on the kind of dream where you are sitting down to an exam without having done a stroke of revision? Or the dream where you find yourself at work having forgotten to put on your trousers? The sequence of events that led to this radical departure from my comfort zone - not so much stepping outside it, but more waving it goodbye and jumping on a plane -

Bitty is a suite of software that allows you to use your smartphone as an interface to your micro:bit. The software comes in two parts. A resident program that you download from here as a HEX file and copy onto your micro:bit and an App that you install on your smartphone (search your app store for Bitty Blue.

Here's a video of me using Bitty Blue to turn a MonkMakes Relay for micro:bit on and off and hence control a motor.

I sometimes get asked how to get started in electronics and so at Maker Faire New York 2017 I gave a short talk on this topic. In particular I looked at how hobby electronics now almost inevitably starts with the use of a microcontroller board like the micro:bit or an Arduino or a single board computer like the Raspberry Pi. The question then arises, which do you pick?
Here are the slides from this presentation. You can also find a video of it here (although there was a lot of noise).

Yet another Arduino clone, but his time a bit different in that is is designed with education and breadboard use as its main goal.

Its on KICKSTARTER now, so take a look if you are interested.
The main features are:Breadboard friendly - clearly labelled pinsArduino Uno compatible (Board Type: Arduino Uno in the Arduino IDE)Low-cost simple designBuilt in USB interface with high quality drivers available (CP2102)Polyfuse over-current protection5V USB poweredBuffered 'L' LED on p

I bought one of these multimeters a few months ago on eBay, to be able to automate the timed taking of readings using a multimeter.

Given the price, I wasn't expecting much, but it works pretty well.

Being a Mac user, I am used to either using software in a Windows XP virtual machine, or searching out alternative software for a device. I this case, I found that a Python library has already been written to decode the multimeter's strange display-based protocol. The proto

I just wanted to share this fairly uninteresting result in case its useful to anyone.
I measured the current drawn from a 5V power supply on both a Raspberry Pi 2 (with Realtek WiFi dongle) and a Raspberry Pi 3 (with built in WiFi) to get an idea of the current consumption while these two boards booted up.
So, with no further ado, here are the results.
Rather as expected - much the same, both settling down to an 'idle current' of around 300mA, booting in under 30 seconds.

When you gave finished using your Raspberry Pi, you should really shut it down, otherwise, its possible to corrupt the SD card image which would mean you having to reinstall Raspbian. Having shut-down your Raspberry Pi you can get it to boot up again by unplugging and plugging the USB lead, but a neater solution is to add a reset button to your Raspberry Pi.

Gooligum Electronics (could they be more Australian?) recently sent me a Joey board to play with.

These boards are incredibly good value at $8 (the American sort of dollar) and a neat design that uses offset holes in the PCB so that it will slide over your Raspberry Pi's GPIO connector while leaving you access to the pins for other uses. This works well, with just the right amount of offset to ensure a good connection without bending the pins.

Having a spare Spark Core doing nothing, it struck me that it would be very easy to pair it up with a large 4 digit 7 segment I2C Adafruit display that I had and make a clock. What's more, because the Spark Core is connected to the Internet via my home network it can get its time from a time server and always be accurate.

Hardware
To make this build, you will need:A Particle Photon or Spark CoreI2C backpack LED display (Adafruit product ID 878 or 1270)Half breadboard2 x 4.7k r

Sometimes its just really handy to be able to plug something into your GPIO pins without having to get out breadboard and jumper wires.

The Raspberry Squid from MonkMakes.com makes does just that.
The Common Cathode RGB LED squid is terminated in female jumper wires and includes series resistors for the LEDs inside the shrink wrap. So, you can just plug it straight onto the GPIO connector.

Its not so hard making your own Raspberry Squid and you can read just how t

The MonkMakes Phobot motor controller board is designed primarily to control a pair of DC motors, to make roving robots that can be controlled over the Internet using the Particle Photon Arduino-ish IoT module. However, you can also use it to drive a bipolar stepper motor.

The stepper motor I used was this 12V motor from Adafruit.

Wire one coil of the stepper (yellow and read wires for my motor) to the M4 screw terminals and the other coil (gray and green) to M3. You wi

I have been using the TMP36 for years, with Arduino, BeagleBone and now the Spark Core/Photon. It has often been reported in the Arduino forums that this chip is inaccurate and unreliable. Indeed a quick glance at the datasheet tells you accurate to 2 degrees C (which seems pretty poor).

I'm working on a Spark Core project for a book and tried out a TMP36. The results seemed totally mad, -25C when it should have been 17C. I checked the maths which was all fine. Then, thinking I had

As you can see, there are a few changes when you compare it to the Raspberry Pi Model B in the middle and the model A on the right. This board is a pretty serious upgrade to the Model B while still being very affordable at just £22.87 + VAT (about $40).

Raspberry Pi, models B+, B and A

The most obvious change is that there are now four USB ports rather than the two of the Model B. This i

The Raspberry Pi uses a pretty modest amount of electricity and it is perfectly possible to run in for short periods using batteries. In this post, I will look at some of the options for making your Pi run on batteries.

How Long Will the Battery Last

Whatever technology you use to battery power your Raspberry Pi, there is one key figure for the battery that you use that will determine how long you will get. This is the battery capacity in mAh (milliamp hours). So, if a

As a teenager, I had one of these calculators and I recently came across a non-functional one advertised on eBay and couldn't resist.
These calculators used a strange battery pack that had two NiCd AA cells, along with a buck-boost chip to raise the voltage to 9V. Of course 30+ years on and in most cases these batteries leak and destroy the buck-boost PCB.
Fortunately its pretty easy to replace the NiCd pack with a PP3 9V battery.

The latest product from MonkMakes is a robot kit that I have designed using the RaspiRobot Board v2 (RRB2). The kit is available from MonkMakes.

Overview

The kit comprises:
* a robot chassis, including two gearmotors and a 6 x AA battery holder.
* a RaspiRobot Board v2 (RRB2) that plugs onto the Raspberry Pi and controls the motors, as well as providing power to the Raspberry Pi itself. It uses a switch-mode power supply that can provide the Pi with up to 2A

Advance your electronics knowledge and gain the skills necessary to develop and construct your own functioning gadgets. Written by a pair of experienced engineers and dedicated hobbyists, Practical Electronics for Inventors, Fourth Edition, lays out the essentials and provides step-by-step instructions, schematics, and illustrations. Discover how to select the right components, design and build circuits, use microcontrollers and ICs, work with the latest software tools, and test and tweak your creations. This easy-to-follow book features new instruction on programmable logic, semiconductors, operational amplifiers, voltage regulators, power supplies, digital electronics, and more.

Thoroughly revised for the new Arduino Uno R3, this bestselling guide explains how to write well-crafted sketches using Arduino’s modified C language. You will learn how to configure hardware and software, develop your own sketches, work with built-in and custom Arduino libraries, and explore the Internet of Things—all with no prior programming experience required!

Electronics guru Simon Monk gets you up to speed quickly, teaching all concepts and syntax through simple language and clear instruction designed for absolute beginners. Programming Arduino: Getting Started with Sketches, Second Edition, features dozens of easy-to-follow examples and high-quality illustrations. All of the sample sketches featured in the book can be used as-is or modified to suit your needs.

With millions of new users and several new models, the Raspberry Pi ecosystem continues to expand—along with many new questions about the Pi’s capabilities. The third edition of this popular cookbook provides more than 200 hands-on recipes that show you how to run this tiny low-cost computer with Linux; program it with Python; hook it up to sensors, motors, and Arduino boards; and even use it with the internet of things (IoT).

Prolific hacker and author Simon Monk also teaches basic principles to help you use new technologies with the Raspberry Pi. This cookbook is ideal for programmers and hobbyists familiar with the Pi through resources such as Getting Started with Raspberry Pi (O’Reilly). Code examples from the book are available on GitHub.

An updated guide to programming your own Raspberry Pi projects

Learn to create inventive programs and fun games on your powerful Raspberry Pi—with no programming experience required. This practical TAB book has been revised to fully cover the new Raspberry Pi 2, including upgrades to the Raspbian operating system. Discover how to configure hardware and software, write Python scripts, create user-friendly GUIs, and control external electronics. DIY projects include a hangman game, RGB LED controller, digital clock, and RasPiRobot complete with an ultrasonic rangefinder.

This fun guide shows how to get started with FPGA technology using the popular Mojo, Papilio One, and Elbert 2 boards. Written by electronics guru Simon Monk, Programming FPGAs: Getting Started with Verilog features clear explanations, easy-to-follow examples, and downloadable sample programs. You’ll get start-to-finish assembly and programming instructions for numerous projects, including an LED decoder, a timer, a tone generator—even a memory-mapped video display! The book serves both as a hobbyists’ guide and as an introduction for professional developers.

Go beyond the basics with this up to date Arduino programming resourceTake your Arduino programming skills to the next level using the hands-on information contained in this thoroughly revised, easy to follow TAB guide. Aimed at programmers and hobbyists who have mastered the fundamentals, Programming Arduino Next Steps: Going Further with Sketches, Second Edition reveals professional programming tips and tricks. This up-to-date edition covers the Internet of Things (IoT) and features new chapters on interfacing your Arduino with other microcontrollers. You will get dozens of illustrated examples and downloadable code examples that clearly demonstrate each powerful technique. Discover how to: •Configure your Arduino IDE and develop your own sketches•Boost performance and speed by writing time-efficient sketches •Optimize power consumption and memory usage •Interface with different types of serial busses, including I2C, 1-Wire, SPI, and TTL Serial •Use Arduino with USB and UART •Incorporate Ethernet, Bluetooth, and DSP•Program Arduino for the Internet •Manage your sketches using One Process•Accomplish more than one task at a time―without multi-threading •Create your own code library and share it with other hobbyists

This hands-on guide will teach you all you need to know to bring your electronic inventions to life!

This fully updated guide shows, step-by-step, how to disassemble, tweak, and re-purpose everyday devices for use in your own electronics creations. Written in the clear, easy-to-follow style that Dr. Simon Monk is famous for, this expanded edition includes coverage of both Arduino AND Raspberry Pi.

Hacking Electronics: Learning Electronics with Arduino and Raspberry Pi, Second Edition, demonstrates each technique through fun DIY projects. Packed with full-color illustrations, photos, and diagrams, the book gets you up and running on your own projects right away. You will discover how to hack sensors, accelerometers, remote controllers, ultrasonic rangefinders, motors, stereo equipment, FM transmitters, and more.

The BBC micro:bit is a tiny, cheap, yet surprisingly powerful computer that you can use to build cool things and experiment with code. The 30 simple projects and experiments in this book will show you how to use the micro:bit to build a secret science lab complete with robots, door alarms, lie detectors, and more--as you learn basic coding and electronics skills.

Here are just some of the projects you'll build: • A "light guitar" you can play just by moving your fingers • A working lie detector • A self-watering plant care system • A two-wheeled robot • A talking robotic head with moving eyes • A door alarm made with magnets

Design custom printed circuit boards with EAGLE

Learn how to make double-sided professional-quality PCBs from the ground up using EAGLE--the powerful, flexible design software. In this step-by-step guide, electronics guru Simon Monk leads you through the process of designing a schematic, transforming it into a PCB layout, and submitting standard Gerber files to a manufacturing service to create your finished board. Filled with detailed illustrations, photos, and screenshots, Make Your Own PCBs with EAGLE features downloadable example projects so you can get started right away.

Install EAGLE Light Edition and discover the views and screens that make up an EAGLE project

Create the schematic and board files for a simple LED project

Find the right components and libraries for your projects

Work with the Schematic Editor

Lay out PCBs with through-hole components and with surface mount technology

If you’re among the many hobbyists and designers who came to electronics through Arduino and Raspberry Pi, this cookbook will help you learn and apply the basics of electrical engineering without the need for an EE degree. Through a series of practical recipes, you’ll learn how to solve specific problems while diving into as much or as little theory as you’re comfortable with.

Author Simon Monk (Raspberry Pi Cookbook) breaks down this complex subject into several topics, from using the right transistor to building and testing projects and prototypes. With this book, you can quickly search electronics topics and go straight to the recipe you need. It also serves as an ideal reference for experienced electronics makers.

This cookbook includes:

Theoretical concepts such as Ohm’s law and the relationship between power, voltage, and current

The fundamental use of resistors, capacitors and inductors, diodes, transistors and integrated circuits, and switches and relays

Recipes on power, sensors and motors, integrated circuits, and radio frequency for designing electronic circuits and devices

Advice on using Arduino and Raspberry Pi in electronics projects

How to build and use tools, including multimeters, oscilloscopes, simulations software, and unsoldered prototypes

Take your Arduino skills to the next level!

In this practical guide, electronics guru Simon Monk takes you under the hood of Arduino and reveals professional programming secrets. Featuring coverage of the Arduino Uno, Leonardo, and Due boards, Programming Arduino Next Steps: Going Further with Sketches shows you how to use interrupts, manage memory, program for the Internet, maximize serial communications, perform digital signal processing, and much more. All of the 75+ example sketches featured in the book are available for download.

Learn advanced Arduino programming techniques, including how to:

Use hardware and timer interrupts

Boost performance and speed by writing time-efficient sketches

Minimize power consumption and memory usage

Interface with different types of serial busses, including I2C, 1-Wire, SPI, and TTL Serial

Use Arduino with USB, including the keyboard and mouse emulation features of the Leonardo and Due boards